Pneumatic tire.



No. 780,519. PATENTED JAN. 24, 1905.

. J. & J. R. MITCHELL.

PNBUMATIC TIRE. APPLICATION FILED MAR.18, 1904.

ai 4a No. 780,519. l Patented January 24, 1905.

UNITED STATES PATENT CEEICE.y

VVINFIELD J. MITCHELL AND JAMES R. MITCHELL, OF LYNN, MASSACHU- SETTS,ASSIGNORS TO FLEXIBLE METAL -MANUFACTURING.CCMPANY, OF LYNN,MASSACHUSETTS, ACORPORATION OF MASSACHUSETTS.

PNEUMATIC TIRE.

, A SPECIFICATION forming part of Letters Patent No. 780,519, datedJanuary 24,y 1905.

Eppntfaionyied March 1s, 1904. semi No. 198,701.

T @ZZ wwm t may 007006771# 14, preferably of fabric, such'ascanvas, anda Be itknown that we,WINFIELD J. MITCHELL comminuted-metal outer layer15, composed, 50

and J AMES R. MITCHELL, of Lynn, in vthe preferably, of powdered iron orsteel and county of Essex and State of Massachusetts, caused to adhereto the fabric layer by a suithave invented certain new and usefulImproveable glue or cement. The outer surface of this ments inPneumaticTires, of whichthefollowlayer is preferably polished orsmoothed, ing is a specification. so as to present a surface againstwhich any 55 The object of this invention is to provide a sharpedged orpointed surface penetrating protector for pneumatic tires having the theouter shoe 11 will tend to glance off. In

I0 ability to resist puncture by pointed or sharp order to make aprotective shoe without puckarticles-such as nails, glass, Sac-andposered inner edges and also to provide a relasessed of a maximum degreeof flexibility, so tively thick tread portion and relatively thin as notto unduly interfere with the resiliency skirt or edge portions, the shoe13 may be of the tire. l made of a middle tread-piece 16, of heavy 1 5To this end the invention in its preferred duck or canvas, and sidepieces 17, of alighter embodiment comprises a protective layer or canvasor fabric, stitched at their edges to the shoe incorporated in the wallof the tire ina edges of the tread-piece. The tread-piece 16 65 suitableplace-as, for instance, between the will preferably be cut in theform ofastraight outer shoe or layerand the inner air-tube-and strip, while theside pieces are cut from a fiat zo composed of an inner layerof iiexiblematerial, strip in annular or semiannular form 'to such as fabric; andan outer layer of comavoid puckered edges. It is obvious, howminutedmetal, such as iron or steel, caused to ever, that the fabric layermight be manufacadhere to the fabric base layer by means of tured in theform of a Woven tube, thickened, cement or glue. The outer surface ofthecomif desired, on the tread portion and cut or slit 2 5 minuted-metallayer is preferably polished yto along its inner Wall. In making theprotectf increase the liability of glancing of the point ive shoe anysuitable method may be followed.

or edge of any sharp substance which pene- For the shoe shown in thedrawings We have 75 trates the outer shoe or layer. found that asuitable method of manufacture Of the accompanying drawings, Figure 1 isto provide an annular mandrel of the cross- 30 represents a sectionalperspective View of a sectional shape of a tire and lay the fabricportion of a pneumatic tire provided with our layer of the shoe thereon.The fabric layer improvement. Fig. 2 represents a cross-secis thencoated with glue or cement and a 8O v tion of the protective shoe. Fig.3 represents layer of powdered iron or steel applied therea plan of thesurface of the shoe before polishto and preferably rolled in underconsiderable 35 ing. Fig. 4c represents a plan View of said surpressure.When the cement is dry, the manface after polishing. drel and shoe arerotated like a wheel and an The same reference characters indicate theemery-stick held up to the comminuted-metal same parts in all thefigures. surface to smooth or polish the same.

In the drawings we have represented a de- A protective shoeconstructedas herein de- 4`O tachable outer-shoe tire of ordinary form,10 scribed does not interfere to an appreciable beingthe rim, and 11thehorseshoe or U'shaped extent with the resiliency of the tire andposouter sho'e, detachably interlocking with said sesses a high degreeof impene'trability. The 90 rim and composed of rubber and fabric.protective shoe also overcomes any bulging 12 is the inner air-tube ofrubber. or protrusion of the inner tube 12 through 45 Loosely positionedbetween the outer shoe large holes or rents in the outer shoe, for theand air-tube is the protective shoe 13, substanreason that it isinextensible and lpuncture and tially U-shaped in cross-section toconform to cut resisting.

. the tire and composed of a flexible base layer It will be obvious thatthe invention is equally applicable to so-called single-tube i vprotective shoe 13 will likewise be preferably located between the outerand inner tubes, as in-the illustration given, only` somewhat moreintimately united to these tubes by' the process yof vulcanization.

We claim- 1. A pneumatic tire containing in its wall a flexible layer ofcomminuted metal having a` polished outer surface.

2. A pneumatic tire containing in its wall a protector composed of aflexible inner base layer, and a comminuted-metal outer layer adheringto said base layer and having a polished outer surface.

8. A protective shoe for pneumatic tires coinprising a iieXible-fabricbase layer curved in cross-sectional outline to conform to thc tire, anda comminuted-metal layer adhering to the outer surface of said baselayer and having a polished outer surface.

In testimony whereof we have aiiixed our signatures in presence of twowitnesses.

WINFIFLD J. Ml'lCHELL. JAMES R. MITCHELL.

Witnesses:

R. M. PInRsoN, A. C. RATIGAN.

